Examine source code of Cowpin

{
  "manifest_version" : 3 ,
  "name" : "Cowpin",
  "version" : "1.4.3",
  "description" : "Save any page or all open tabs to Cowpin — tags, read-later, private.",
  "permissions" : [
    "activeTab" ,
    "tabs" ,
    "contextMenus" ,
    "storage" ,
    "notifications" ,
    "scripting" 
  ],
  "host_permissions" : [
    "https://www.cowpin.com/*" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "cowpin@cowpin.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "bookmarksInfo"
        ]
      }
    }
  },
  "action" : {
    "default_popup" : "popup.html",
    "default_title" : "Save to Cowpin",
    "default_icon" : {
      "16" : "icons/icon16.png",
      "48" : "icons/icon48.png",
      "128" : "icons/icon128.png"
    }
  },
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "icons" : {
    "16" : "icons/icon16.png",
    "48" : "icons/icon48.png",
    "128" : "icons/icon128.png"
  },
  "commands" : {
    "_execute_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+Period",
        "mac": "Command+Shift+Period"
      },
      "description" : "Open Cowpin save popup"
    }
  }
}